Many patented applications of inductive charging now specifically reference the wireless or inductive charging of mobile electronic devices in both indoor environments and also within vehicles so as to remove the clutter and need for various charging cables that interface to the different devices. Inductive coupling frequently uses the application of charging pads, cradles or holders that incorporate mechanical, magnetic or printed means of providing or indicating alignment of the primary and secondary inductive coils to enable and obtain optimal transfer efficiencies between the primary transmit circuit and the receiving secondary circuit. Other patents discuss the application of multiple primary coils arranged in various arrays, so that the device to be charged can be placed in a variety of locations or orientations on the flat pad charging device.
For those devices that are placed in vehicles, Sarnowsky in D572,189 S shows the implementation of in-vehicle inductive charging to a mobile device placed within a cup holder, while Baarman in U.S. Pat. No. 7,612,528 describes the charging of devices placed within a holder that maybe located in the vehicle console, sun visor, trunk, seat pocket, door stowage compartment and glove compartment. Baarman also describes the ability of a removable device to wirelessly communicate with the vehicle data bus when placed within the holder for the purposes of transferring voice, audio and device charge status data to the vehicle. In U.S. Pat. No. 7,462,951, Baarman describes the application of inductive charging to hand held tools where a tool box, which may be placed within a vehicle and connected to vehicle power, is equipped with inductive charging locations into which a portable power tool can be placed to receive a charge. Vitito in U.S. Pat. No. 8,203,657 describes the inductive charging of mobile entertainment system embedded within a car seat headrest. Soar in US Patent Application US2013/0005251 A1 01, 2013 describes the charging of a central battery within a tactical vest.
None of the references cited describe the provision of wireless power to a tactical garment with a central rechargeable battery(ies) and or soldier power management charger that in turn provides power to vest mounted distributed electronic devices within a battlefield environment, within a vehicle, vessel or aircraft or in a forward or rear operating base or barrack. With the exception of Soar, the above mentioned prior art describes the application of inductive chargers in a clean indoor type of environment such as on top of furniture, within gloves boxes or in vehicle consoles where both the charger and the device are not envisioned to be exposed to harsh environmental elements. The proposed invention is seat or support mounted inductive charging system for a tactical vest with central battery which is suitable for application in a harsh environment.
Soar in US Patent Application US2013/0005251 A1 01, 2013 does describe the charging of a central battery within a tactical vest using inductive power transfer. Soar describes using large planar coils that are placed in a vertical or matrixed array configurations to accommodate different soldier torso lengths and provide primary to secondary coil alignment for efficient inductive coupling, wherein there is loss of inductive coupling when the soldier moves in his seat and so as to create a horizontal separation distance sufficient to both significantly decrease the inductive coupling efficiency and therefore inductive power transfer efficiency to pre-determined cut-off points. In addition as the distance between the planar primary and secondary coils is increased the radiation of magnetic energy into free space also increases. This stray magnetic flux may cause electromagnetic interference (EMI) to other electronic systems that requires additional shielding or mitigation strategies.
As the soldier moves about in his seat and depending on the number of items carried on his back, such as a water pouch, radios or other devices, the separation distance between the secondary coil on the soldier and primary coil in the seat back will vary. When the coils are in close proximity the coupling efficiency is high, however as the separation distance is increased to greater than about 2.5 cm (one inch) the power transfer efficiency of the system will decrease. This both decreases the charge rate of the central soldier battery and power transfer inefficiency places increased burden on the vehicles electrical system, given eight to ten troops within the vehicle. A further consequence of the planar coil system is that the secondary coil carried by the soldier, if backed by ferrite material, may represent a significant additional weight that must be carried by the soldier.
Suggestions of a system such as described by Soar but using magnetic resonance for the wireless power transfer actually exacerbates the above problems, for as the standoff between the seat mounted primary coil and secondary coil on the soldiers garment increases the magnetic power radiated by the primary coil continues to be transmitted over larger distances rather than being converted to energy by the secondary coil (FIGS. 2A and 2B).